Is Windows Phone 7 too little too late?
Another strong point is made by looking at the loyalty statistics of current smartphone users. They note that 89% of iPhone users and 71% of Android users intend to maintain their current operating system on their next phone purchase. One possible explanation for this loyalty is the expensive volume of apps that consumers accumulate, which they would have to replace if they switched to another OS.
While the article doesn't give much hope for Windows Phone 7 in terms of market penetration, we shouldn't take this to mean it won't be a great OS. Windows Phone 7 might well carve out its own corner of the mobile market from its competitors.
source: The Motley Fool via MS Mobiles